<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>new css1</title>
    <link rel="stylesheet" href="newcss1.css">
</head>
<body>
<div class="c1">div1</div>
<div class="c2">div2</div>
<div class="c3">div3</div>
<div class="c4">
    div4
    <div class="c5">div5 in div4</div>
    <div class="c6">div6 in div4</div>
</div>

</body>
</html>